To understand why Permanent Magnet Motors can be beneficial for a variety of motor needs, it may be helpful to know what permanent magnets are. They are magnets that maintain their own persistent magnetic fields. Rare earth magnets, powerful magnets made from rare earth metals, are the type typically used for this purpose. Rare earth magnets are not particularly rare, they just happen to come from the class of metals known as rare earth metals. There are other metals that only become magnetic when magnetized by an electric field and only stay magnetized as long as that electric field is in place. This concept is at the heart of how PM motors work.
In PM motors, a wire winding serves as an electromagnet when electricity passes through it. The electromagnetic coil is attracted to the neodymium magnet, and this attraction is what causes the motor to rotate. When the source of electrical power is removed, the wire loses its magnetic qualities and the motor stops. In this way, the rotation and motion of PM motors can be managed by a motor driver that controls when and for how long electricity and, by extension, the electromagnet, allows for rotation of the motor.
Post time: 06-01-2016